Immunomodulating Activities of Sodium-dodecyl-sulphate-extracted Antigens fromActinobacillus actinomycetemcomitansSerotype b

Abstract

Actinobacillus actinomycetemcomitans (serotype b) whole lysates, LPS-free cell wall polymers (CWP) and CWP fractions obtained by immunoblot were assayed for immunomodulating activity. Whole cell lysates and purified CWP stimulated mouse splenocytes to proliferate in vitro . Five CWP fractions, ranging from 15 to 209 kDa, suppressed in vitro splenocyte proliferation. Fraction-induced inhibition of proliferation was not due to cytotoxicity. Purified A. actinomycetemcomitans CWP stimulated murine splenocyte interleukin-1 release during 72 h of in vitro culture. Two CWP fractions preferentially stimulated splenocyte interleukin-4 release during in vitro culture. This mixed response of CWP-induced splenocyte stimulation and suppression, and IL-l/IL-4 release, is dependent on fragment size. Therefore, A. actinomycetemcomitans CWP may play a role in the inflammatory process of periodontal disease as large bacterial fragments stimulate inflammation and smaller, degraded fragments promote anti-inflammatory activities. Keywords - Actinobacillus actinomycetemcomitans , Cell wall polymers, Periodontal disease, Cytokines.